how to calculate glcm ?

Hi, here I have code for calculate glcm using graycoprops(); and manual calculated. When I run in comman window using graycoprops() I get result. But in manual code the result is 0. Any explain and have will good. thanks !

[fname, pathname]=uigetfile({'*.bmp*','Input image'}); fname = fullfile(pathname, fname); im=imread(fname);

[~, foldername, ext] = fileparts(fname);

gray = rgb2gray(im);

%using toolbox

glcm = gray;

stats = graycoprops(glcm);

%manual calculated

S = size(gray, 1);

if any(gray(:))

    prob = gray./sum(gray(:));

end

prob_norm = gray ./ sum(gray(:));

u = mean2(prob_norm);

py = sum(prob_norm,1);

px = sum(prob_norm,2);

contr = 0; energ = 0; homom = 0; %corr = 0;

for i = 1:S for j = 1:S

        energ = energ + prob_norm(i,j)^2;
        contr = contr + prob_norm(i,j).*(i-j)^2;
        homom = homom + prob_norm(i,j)/(1+(i-j)^2);
        %co    = i*j*prob(i,j);
     end
end

% Correlation

%ux = mean(px); sx=std(px);

%uy = mean(py); sy=std(py);

%corr =(sum(co(:))-(ux*uy))/(sx*sy);

    Stat.Contrast = contr;
    Stat.Homogeneity = homom;
    Stat.Energy = energ;
    %Stat.Correlation = corr;
    disp ('========== Fitur Tekstur GLCM ==========')
    disp(strcat(['Contrast = ',num2str(contr)]))
    disp(strcat(['Homogenitas = ',num2str(homom)]))
    disp(strcat(['Energy = ',num2str(energ)]))

[Image Analyst]

http://www.mathworks.com/matlabcentral/answers/13205#answer_18099

[Oman Wisni]

yes sir I will replay to ask and attached my code. I want calculate GLCM using formula which I get from haralick to know did the result same or not.

I already using graycoprops(); But when I using formula to calculate the result 0.

In below I have an image and my code :

S = size(gray, 4);

if any(gray(:))
    prob = gray./sum(gray(:));
end

prob_norm = gray ./ sum(gray(:));

u = mean2(prob_norm);
py = sum(prob_norm,1);
px = sum(prob_norm,2);

contr = 0;
energ = 0;
homom = 0; 
corr = 0;

for i = 1:S
    for j = 1:S

          energ = energ + prob_norm(i,j)^2;
          contr = contr + prob_norm(i,j).*(i-j)^2;
          homom = homom + prob_norm(i,j)/(1+(i-j)^2);
          co    = i*j*prob(i,j);
       end
  end

%Correlation
ux = mean(px); sx=std(px);
uy = mean(py); sy=std(py);
corr =(sum(co(:))-(ux*uy))/(sx*sy);

      Stat.Contrast = contr;
      Stat.Homogeneity = homom;
      Stat.Energy = energ;
      Stat.Correlation = corr;

[Oman Wisni]

Which one I wrong declarad that code? Or my code not complete so the result was 0